A dimension and tolerance data model for concurrent design and systems integration

Dimensions and tolerances are critical engineering design information for defining shape requirements of manufactured parts. As technologies for new design analysis and manufacturing planning are being developed, they must be seamlessly integrated into a computer-aided product development environment. A data model is an effective technique to define the shareable semantics that are essential to the success of data communication in an integrated environment. This paper introduces a dimension and tolerance data model developed for the foundation of ISO 10303 Part 47. This model is a component of an overall product data model. The model has three major components: dimension schema, tolerance schema, and datum and shape aspect schema. These schema specify data resources and structures for describing dimension and tolerance characteristics of products. Based on this model, descriptions of dimensions and tolerances of products can be communicated between tolerance-related software application systems.